Around 200,000 cubic metres of gas have been escaping from the installation each day since the emergency began.
Christian Bussau, chief scientist and ocean expert at Greenpeace, who is on board the vessel, said there was “oil on the water surface” and a “chemical” smell in the air. Samples are being sent for analysis at a German laboratory to find out what is creating the sheen on the surface.
Mr Bussau said: “Although we are five kilometres away, we can feel here that this is contaminating and polluting the environment and this is dangerous for the environment and for the climate.
“The Greenpeace team has a sophisticated gas detection camera which may reveal more about the gas leak, although the conditions and site restriction may make this difficult.”
He added: “Elgin is yet another example where the industry has lost control of a well. After more than a week of publishing the accident, there is still no information [about] how long Total will need to close the gas leak.”